--  @testpoint:opengauss关键字close(非保留)，作为函数名
--关键字不带引号-成功
drop function if exists close;
create function close(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/
--清理环境
drop function close;

--关键字带双引号-成功
drop function if exists "close";
create function "close"(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/
--清理环境
drop function "close";

--关键字带单引号-合理报错
drop function if exists 'close';
create function 'close'(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/

--关键字带反引号-合理报错
drop function if exists `close`;
create function `close`(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/